Answer in brief
CVE-2026-23083 records a High severity (CVSS 7.8) vulnerability in fou: Don't allow 0 for FOU_ATTR_IPPROTO.. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-23083 records a High severity (CVSS 7.8) vulnerability in fou: Don't allow 0 for FOU_ATTR_IPPROTO.. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <c7498f9bc390479ccfad7c7f2332237ff4945b03 || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <611ef4bd9c73d9e6d87bed57a635ff1fdd8c91ea || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <6e983789b7588ee59cbf303583546c043bad8e19 || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <1cc98b8887cabb1808d2f4a37cd10a7be7574771 || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <b7db31a52c3862a1a32202a273a4c32e7f5f4823 || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <9b75dff8446ec871030d8daf5a69e74f5fe8b956 || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <7a9bc9e3f42391e4c187e099263cf7a1c4b69ff5 | c7498f9bc390479ccfad7c7f2332237ff4945b03, 611ef4bd9c73d9e6d87bed57a635ff1fdd8c91ea, 6e983789b7588ee59cbf303583546c043bad8e19, 1cc98b8887cabb1808d2f4a37cd10a7be7574771, b7db31a52c3862a1a32202a273a4c32e7f5f4823, 9b75dff8446ec871030d8daf5a69e74f5fe8b956, 7a9bc9e3f42391e4c187e099263cf7a1c4b69ff5 |
| Linux/Linuxgeneric | 3.18 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
Published upstream
Feb 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
In the Linux kernel, the following vulnerability has been resolved: fou: Don't allow 0 for FOU_ATTR_IPPROTO. fou_udp_recv() has the same problem mentioned in the previous patch. If FOU_ATTR_IPPROTO is set to 0, skb is not freed by fou_udp_recv() nor "resubmit"-ted in ip_protocol_deliver_rcu(). Let's forbid 0 for FOU_ATTR_IPPROTO.
Quoted source text, attributed separately from HOL analysis.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <c7498f9bc390479ccfad7c7f2332237ff4945b03 || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <611ef4bd9c73d9e6d87bed57a635ff1fdd8c91ea || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <6e983789b7588ee59cbf303583546c043bad8e19 || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <1cc98b8887cabb1808d2f4a37cd10a7be7574771 || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <b7db31a52c3862a1a32202a273a4c32e7f5f4823 || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <9b75dff8446ec871030d8daf5a69e74f5fe8b956 || >=23461551c00628c3f3fe9cf837bf53cf8f212b63 <7a9bc9e3f42391e4c187e099263cf7a1c4b69ff5 | c7498f9bc390479ccfad7c7f2332237ff4945b03, 611ef4bd9c73d9e6d87bed57a635ff1fdd8c91ea, 6e983789b7588ee59cbf303583546c043bad8e19, 1cc98b8887cabb1808d2f4a37cd10a7be7574771, b7db31a52c3862a1a32202a273a4c32e7f5f4823, 9b75dff8446ec871030d8daf5a69e74f5fe8b956, 7a9bc9e3f42391e4c187e099263cf7a1c4b69ff5 |
| Linux/Linuxgeneric | 3.18 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
Published upstream
Feb 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
In the Linux kernel, the following vulnerability has been resolved: fou: Don't allow 0 for FOU_ATTR_IPPROTO. fou_udp_recv() has the same problem mentioned in the previous patch. If FOU_ATTR_IPPROTO is set to 0, skb is not freed by fou_udp_recv() nor "resubmit"-ted in ip_protocol_deliver_rcu(). Let's forbid 0 for FOU_ATTR_IPPROTO.
Quoted source text, attributed separately from HOL analysis.